The present invention concerns a retaining device for retaining a ski boot on a ski, snowboard, or the like. The invention concerns, more particularly, an improvement of the frontal binding which retains, in releasable fashion, the front end of the user""s boot on a ski. However, it is to be appreciated that the invention is also applicable to other applications and is not limited to the aforementioned applications.
In general, the boot of a skier is retained on the ski in a disengageable fashion at its front end by a frontal binding commonly called a xe2x80x9cthrust restraintxe2x80x9d and at its rear end, specifically at its heel, by a rear binding commonly called a xe2x80x9cheel restraintxe2x80x9d.
In case of significant stresses, when the leg or the joints of the skier are in danger, the release of the ski boot takes place either from the front or from the rear of the boot or from both locations at once. To that end, the thrust restraint typically comprises a jaw which pivots at least laterally around a vertical axis. The heel restraint typically comprises a jaw which pivots in an upward direction around a transverse axis. The jaws of the thrust and heel restraints are each acted upon by an elastic system including a release or disengagement spring, whose compression is regulated in order to provide the skier with an assured stress value for the release of his boot.
Many front safety bindings are known which hold the front of a boot on a ski to permit skiing while providing for boot release when the leg appears to be under dangerous stress. These thrust restraints include a pivoting jaw, acted upon in centered retaining position by an elastic system, such as a spring.
The present invention contemplates a new and improved apparatus which is very compact, comprises a minimum of parts, and retains the front end of the boot in a releasable manner according to which the zone towards the front beyond that of the jaw is released.
According to one aspect of the invention, a binding more particularly adapted to releasably retain the front end of an associated boot of a skier is disclosed. The binding includes a movable jaw which pivots on a base around a vertical axis against the action of elastic return means. The elastic return means includes two actuating arms, acted upon by an elastic system. Each of the actuating arms pivots around a pivoting axis independently from the jaw. The jaw cooperates with the actuating arms via a driving element, which is an integral part of said elastic return means. The driving element is arranged beneath the front end of the boot, behind the transverse plane passing through the pivot axis of the jaw. The elastic system can be of any type, such as, for example, of the type functioning on compression or on tension or on twisting.
According to another aspect of the invention, the two actuating arms are acted upon by the elastic system against at least one fixed support stop. The driving element includes a cylindrical projection extending toward the bottom and whose axis is beneficially arranged in back in relation to the pivot axis of the jaw.
According to another aspect of the invention, each of the two arms is a lever of the third kind, according to which the application point of the force is arranged between the point of support, i.e. the pivoting point of the arm and the point of resistance, i.e. the point of application of the elastic system.
According to another characteristic, the driving element is connected to the jaw by the intermediary of a front plate which extends somewhat horizontally, and on which the bottom of the front of the sole of the boot may rest in order to constitute support means towards the bottom for same.
Preferably, the driving element is a cylindrical projection which is preferably retained in centered position by two actuating rails, realized on two actuating arms. Each of the two actuating rails are preferably realized by the front edge of the first portion of an actuating arm. Each rail preferably further includes a first portion of the rail, or retaining rail, which is extended by a second portion of the rail, or disengagement rail. The passage of the actuating element of the first portion of the rail at the second portion of the rail thus ensures that the disengagement force value releases the boot.
Preferably, the retaining device according to the invention is characterized in that each of the actuating arms, the left arm and the right arm, is respectively articulated around a pivot axis. Each actuating arm preferably stretches out beneath the zone occupied by a first portion of the end of the boot and extends in the direction of the plane of symmetry. Each actuating arm additionally includes a second portion which extends side by side toward the rear. The extremities of the second portions of the two actuating arms are acted upon by the elastic system against the fixed stop.
In one embodiment, the base is fixed to the ski, whereas in another embodiment the retaining device is arranged at the front of a pivoting plate articulated at its front end around a transverse pivot axis.
According to yet another embodiment, the base is articulated around the transverse pivot axis in order to be extended toward the rear so as to constitute the pivoting plate. The pivoting plate includes at the front the retaining jaw, and at the rear the retaining means which retains the rear of the boot.
It is to be appreciated that the embodiment of the binding which releases the front zone of the jaw is adapted for cross-country skis which require heel play for the user when moving.
Other advantages of the invention will be evident to those of ordinary skill in the art from the examples described in the following detailed description and the attached drawings.